# Python package to assess text coherence

I am looking for a python package that calculates how well one sentence of a natural text follows the next. One could simply count how many identical words are in the next sentence but the better method would be to compare word similarities using something like word vectors (=semantically similar words instead of exact matches or synonyms).

Coherent:

Tom loves reading books.
He prefers reading books at library.
So he always goes to library.


Non-coherent:

Tom loves reading books.
He missed his lunch today.
So he always goes to library.


I guess there must be several well written packages for such an automatic assessment (or similar methods) but I just can't find it. Any ideas?